The shooting occurred around noon Saturday at the Canfield Green Apartment complex. Ferguson police confirmed it was one of their officers who opened fire.

Family members identified the shooting victim as 18-year-old Michael Brown. Desiree Harris, who says Brown is her grandson, says she found his body in the middle of the street minutes after he was expected to arrive at her home in suburban St. Louis neighborhood.

Officer Brian Schellman, spokesman for the St. Louis County Police Department, said "a couple hundred" people came out of area apartment buildings after an officer with the Ferguson Police Department shot and killed the teen. Schellman did not say what prompted the shooting.

Schellman said some people yelled threats toward the police, and officers said they thought they heard gunshots from the crowd. According to The Associated Press, some in the crowd yelled "kill the police."

There were no reports of additional injuries, Schellman said.

After the crowd gathered, police at the scene called for about 60 other police units to respond to the area in Ferguson, which is a city of about 21,000 residents located a few miles north of downtown St. Louis. He said the crowd was under control by about 5 p.m. and several of the additional officers had left the area.

The St. Louis County NAACP said it has launched an investigation and asked the FBI to intervene.